Response to novelty in low-stress conditions in rats

Thirteen inbred August rats were tested in an exploration box. The box was divided into three zones: start zone, tunnel zone, and screen zone. All animals were familiarized with the experimental chamber by being placed there for consecutive days. Each daily session lasted nine minutes. In the eleventh session, the chamber was slightly changed. In the screen zone, a different visual pattern was displayed. In the tunnel zone, the arrangement of tunnels was changed. Rats responded to novelty with increased walking, object contacts, air sniffing, rearing, climbing, and decreased floor sniffing. Introducing novelty resulted in a shortened time spent in the start and tunnel zone, and prolonged time spent in the screen zone. The subjects showed no emotional response, such as: freezing, grooming, or burying. The role of changes in intensity, complexity and temporal dynamics is to be tested in the follow-up studies.